Don't worry, your stats never reset unless you ask it to with a console command. If you see all your stats at 0, it's because you've lost connection to the Steam master server which is where all the stats are stored. This usually happens during Steam server maintenance, or sometimes you just need to restart Steam.

I do know how long it takes. I'm level 99 with almost hero on everything. I'm not exactly sure how your stats reset without using the console command to do so. I suggest you go complain on the official TWI forums.

1 - erase the RO2 data in my documents (and make a back up copy in another folder just in case) 2 - unistall the game in steam and re-start steam.3- download the game again, and re-start steam. Normally your stats will not be lost (i did this procedure when the workshop patch made my ro2 get crashed, and my stats are still here).you will get a version of ro2 including all the patches.